Automatic flash selection device for cameras

ABSTRACT

An automatic flash selection device for use with fully automatic exposure setting cameras comprising an exposure meter pointer, stopper plate and a coacting detector plate which are displaced in response to the actuation of the shutter release, a distance proportional to the angle of rotation of the pointer in that the plates are blocked during their displacement by the pointer when its angle of rotation is less than a predetermined angle, but are displaced to the full length of their strokes when the angle is beyond a predetermined angle; a pivoted first lever coupling the detector plate and the shutter stop mechanism; a pivoted intermediate lever rotated by the first lever and coupled to the shutter speed selection lever; a focusing cam operated by the focusing mechanism and a pivoted third lever abutting the intermediate lever and the shutter stop mechanism. When there is adequate light on the subject, the first lever controls the shutter stop mechanism in response to the proportional displacement of the detector plate. However, when there is insufficient light, the detector and stopper plate will pass through their full displacement, rotating the first and intermediate levers through a greater range, such that the third lever is disconnected from engagement with the intermediate lever and switches control of the shutter stop mechanism from the first lever to the focusing cam, while the stopper plate actuates a warning light in the flash equipment and the shutter speed selection lever is moved to a position causing the shutter speed mechanism to be operated at a low shutter speed. Thus, when the flash is to be used, the shutter stop mechanism is under the control of the focusing mechanism and the shutter speed is appropriately lowered.

United States Patent Kaneko et al.

[54] AUTOMATIC FLASH SELECTION DEVICE FOR CAMERAS [72] Inventors:Hirokazu Kaneko, Tokyo, Japan; Ricoh Co., Ltd., Tokyo, Japan 22 Filed:Dec. 17, 1970 21 App1.No.: 98,991

[58] Field of Search.

....... ..95/11 R, 10C, 64, 64A, 11.5R

[56] References Cited UNlTED STATES PATENTS 3,400,646 9/1968 Kiper et a1..95/64 R 3,464,333 9/1969 Aoki et al 3,498,192 3/1970 Ito et al 95/64 R...95/11 R ...95/64 R 3,500,731 3/1970 Bresson et al. 3,529,524 9/1970Ueda 3,555,985 1/1971 Ueda ..95/10 C Primary Examiner-Samuel S. MatthewsAssistant Examiner-Robert P. Greiner Attorney-Henry T. Burke, RobertScobfy, Robert S. Dunham, P. F. Henninger, Lester W. Clark, Gerald W.Griffin, Thomas F. Moran, R. Bradlee Boal and Christopher C. Dunham 51July 25, 1972 [57] ABSTRACT An automatic flash selection device for usewith fully automatic exposure setting cameras comprising an exposuremeter pointer, stopper plate and a coacting detector plate which aredisplaced in response to the actuation of the shutter release, adistance proportional to the angle of rotation of the pointer in thatthe plates are blocked during their displacement by the pointer when itsangle of rotation is less than a predetermined angle, but are displacedto the full length of their strokes when the angle is beyond apredetermined angle; a pivoted first lever coupling the detector plateand the shutter stop mechanism; a pivoted intermediate lever rotated bythe first lever and coupled to the shutter speed selection lever; afocusing cam operated by the focusing mechanism and a pivoted thirdlever abutting the intermediate lever and the shutter stop mechanism.When there is adequate light on the subject, the first lever controlsthe shutter stop mechanism in response to the proportional displacementof the detector plate. However, when there is insufiicient light, thedetector and stopper plate will pass through their full displacement,rotating the first and intermediate levers through a greater range, suchthat the third lever is disconnected from engagement with theintermediate lever and switches control of the shutter stop mechanismfrom the first lever to the focusing cam, while the stopper plateactuates a warning light in the flash equipment and the shutter speedselection lever is moved to a position causing the shutter speedmechanism to be operated at a low shutter speed. Thus, when the flash isto be used, the shutter stop mechanism is under the control of thefocusing mechanism and the shutter speed is appropriately lowered.

1 Claim, 4 Drawing Figures AUTOMATIC FLASH SELECTION DEVICE FOR CAMERASBACKGROUND OF THE INVENTION The present invention relates to anautomatic flash selection device for use with a fully automatic exposuresetting camera having a built-in socket for a flash light source such asa flash bulb, flash cube and the like, said device being capable ofautomatically selecting either the automatic exposure setting or theflash exposure setting in response to the brightness of a subject.

Cameras are known having built-in flash equipment and associated devicesdrivingly coupled to a focusing ring or the like and to an aperture ringfor automatically setting the aperture stop in accordance with thedistance between the subject and the camera by means of previouslysetting a guide number of a flash light source to be used. In additionthere has been proposed an automatic flash selection device incorporatedin a fully automatic exposure camera having a built-in exposure meter,in which device the difference in the amount of the displacements of apointer stopper plate which is moved to engage the pointer of theexposure meter is detected and used to automatically setting the camerato a low shutter speed exposure while opening or closing a power sourcecircuit for a previously loaded flash light source. The aperture stop isset by the exposure meter pointer when the power source circuit isopened and when the power source circuit is closed the aperture stop isset by a focusing member. However, the conventional devices of the typedescribed above are complicated in construction, expensive tomanufacture and unreliable in operation.

SUMMARY OF THE INVENTION According to the present invention a series ofinteracting pivoted levers is provided wherein the initial actuationrange of one lever coupled to an aperture stop setting member andinterconnecting a toothed plate which detects the position of thepointer of the exposure meter with an apertureblade-driving member isdefined as the range in which the aperture stop setting is under thecontrol of the automatic exposure setting and the remaining range of thelever is defined as the range under the control of the focusing andaperture stop setting operated with the flash exposure setting.

The toothed plate is coupled to the aperture blade driving leverdepending upon the initial displacement of the lever interconnecting thetoothed plate for pressing the pointer of the exposure meter and theaperture blade driving lever so that the fully automatic exposure setmay be accomplished. In response to the subsequent displacement of thelever, the shutter speed selection lever is moved away from the path ofrotation of the shutter blade thereby providing a slow shutter speedwhile the lever coupled to the focusing ring is engaged with thefocusing cam thereby driving the lever coupled to the aperture settingring so as to set an aperture stop.

The present invention provides therefore a flash selection device simplein construction and reliable in operation.

The present invention becomes more apparent from the description of thepreferred embodiment thereof taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWING Referring to FIG. 1, a lever 3 coupledto an aperture stop setting member is rotatably mounted to a base 1 inthe camera housing by a pin 2 and is provided with a projection 3a and abifurcated end 3b. A spring 4 is loaded between the lever 3 and thebase 1. An intermediate lever 6 having pins 6a and 6b is rotatablypivoted to the base 1 by a pin 5. A spring 7 is loaded between the base1 and the intermediate lever 6 so as to move the pin 6a toward theprojection 3a of the lever 3 while the pin 6b is loosely received in abifurcated end 9a of a speed-selection lever 9 pivotably mounted to thebase by a pin 8. A shutter blade 10 for opening and closing an aperture1a for a camera lens formed through the base 1 is pivotably mounted tothe base 1 by a pin 11. When the shutter blade 10 is rotated in thecounterclockwise direction, a stepped portion 10a of the shutter blade10 engages with the leading end 9 b of the speed-selection lever 9. Abase 12 of an exposure meter is securely fixed to the upper portion ofthe base 1 and an arcuate groove 12a whose center is the axis of a meter13 is formed through the base 12. The upright end of a pointer 14 of themeter 13 is fitted into and extends through the groove 12a duringrotation. Both a pointer stopper plate 15 and a toothed plate 16 aremounted to the base 12 by a suitable mechanism consisting of a guide pinand a slot for lateral movement. A relatively weak spring 17 is loadedbetween the pointer stopper plate 15 and the toothed plate 16. A pin 16aextending from the toothed plate 16 is fitted into the bifurcated end 3bof the lever 3. When the pointer stopper plate 15 is moved to the leftin FIG. 1, a projection 15a formed integral with the stopper plate 15closes a contact A fixed to the base 1.

Referring to FIGS. 2 and 3, a lever 19 drivingly interconnected with afocusing ring is pivotably mounted to the base 1 by a pin 18. A spring20 is loaded between the lever 19 and the base 1 so that one end 19a ofthe lever 19 may be normally in contact with the pin 6b of the lever 6.A shutter blade driving lever 22 is pivotably mounted to the base 1 by apin 21 and a spring 23 is loaded between the lever 22 and the base. Apin 22a extending from the lever 22 is fitted into elongated slots 25aand 26a of shutter blades 25 and 26 pivoted to the base 1 by a pin 24and is in opposed relation with the ends of the levers 3 and 19. A pin19c extending from the lever 19 may detachably engage with a focusingcam 27 made integral with a focusing ring and rotatable about theoptical axis. The forces of the springs 4, 7, 20, and 23 are reduced inorder named. That is, the spring 4 is strongest while the spring 23weakest.

FIG. 4 illustrates the circuit diagram of the instant embodiment. Thecontact A is closed and opened by a projection 15a on the pointerstopper plate 15; contact B is an X contact which is closed when theshutter is opened; C is a warning lamp; D is a flash lamp or flash lightsource; and E is a power source.

Next the mode of operation will be described for the case when thebrightness of a subject is sufficient to actuate the exposure meter. Thelever 3 is set free through an appropriate mechanism (not shown) upondepression of a shutter release button or the like, so that the lever 3is rotated in the counterclockwise direction by the spring 4. Inconsequence, the toothed plate 16 is displaced to the left by thecoaction of the bifurcated end 3b of the lever 3 with the pin 16a of thetoothed plate 16. The pointer stopper plate 15 is also caused todisplace toward the left together with the toothed plate 16 under theforce of the spring 17 so that the arcuate edge of the stopper plate 15presses the upstanding end of the pointer 14 against the arcuate edge ofthe groove 12a of the meter base 12. Thus the displacement of thepointer stopper plate 15 is stopped. When the lever 3 is furtherrotated, only the toothed plate 16 is displaced further to the leftextending the spring 17 a distance proportional to the rotationalposition of pointer 14 until it is stopped when the toothed portion atthe leading end thereof engages with the pointer 14. The rotation oflever 3 in the counterclockwise direction also permits movement of thepin 22a of the driving lever 22 so that the lever 22 is rotated in thecounterclockwise direction under the force of the spring 23 therebyopening the blades 25 and 26. When the lever 3 is stopped by engagementof the pointer 14 with plate 16, the blades 25 and 26 are stopped tothereby define the proper aperture stop in response to the angle ofrotation of the pointer 14 of the meter 13. In this case, the projection15a on the pointer stopper plate 15 will not close the contact A so thatthe flash-light source D is not energized.

The intermediate lever 6 is in a position in which the pin 6a is not inengagement with the lever 3 so that it is free to move somewhat in aclockwise direction under the action of spring 7 and the leading end 9bof the lever 9 is moved within the path of rotation of the shutter blade10 as viewed from FIG. 1. The shutter blade 10 which is rotated to openby another shutterblade driving lever (not shown), in response to thedepression of the shutter release button, strikes the lever 9immediately after passing across the aperture 1a and is sprung back. Inconsequence the shutter blade 10 is returned to its initial position athigh speed with the aid of a return spring (not shown), so that a highshutter speed exposure may be attained.

The pin 6b on the other end of the intermediate lever 6 moves intoengagement with the one end 19a of the lever 19 causing the lever 19 torotate the counterclockwise direction against the spring 20 so as to bemoved away from the blade driving pin 22a, and avoid engagement of thepin 196 with the focusing cam 27. Therefore the aperture blades 25 and26 are not driven through the lever 19 when the camera is focused andthe aperture stop is controlled only in response to the position of thepointer 14 of the meter 13. Thus the automatic pressure setting isattained.

Next when the brightness of the subject is not sufficient to drive theexposure meter or to cause the pointer 14 to swing into a predeterminedrange, the upright end of the pointer 14 is moved out of the path of thepointer stopper plate 15 and the toothed plate 16 as viewed from FIG. 1.Then rotation of the lever 3 in the counterclockwise direction under theforce of the spring 4 upon the depressing of the shutter release buttonor the like, causes the pointer stopper plate 15 and the toothed plate16 to be displaced to the left extremities of their strokes so that theprojection 15a of the pointer stopper plate 15 closes the contact A. Thewarning lamp C is energized giving a warning that flash photography isnecessary. The projection 3a of the lever 3 pushes the pin 6a of theintermediate lever 6 so as to rotate the level in the counterclockwisedirection against the spring 7. The pin 6b of the intermediate lever 6is released from engagement with the lever 19 so that the latter isrotated in the clockwise direction under the force of the spring 20,thereby engaging the pin 19c with the stepped portion of the focusingcam 27. In this case the leading end 18b of the lever 19 pushes the pin22a so as to drive the aperture blades 25 and 26. Since the lever 3 ismoved away from the pin 22a, the aperture stop is varied only inresponse to the operation of the focusing cam when setting a distancebetween the subject and the camera lens. The pin 6b causes the lever 9to rotate in the counterclockwise direction so that the leading end 9bis moved away from the path of rotation of the shutter blade 10. Inconsequence the shutter blade 10 may rotate in the counterclockwisedirection until it strikes a stopper (not shown) after it opens theaperture la and then may return to its initial position by its ownreturning force. Thus a lower shutter speed exposure is set. The flashphotography may be accomplished by energizing the flash-light source Dby closing the contact B.

In one variation of the present invention, a shutter speed may be fixedwhile the autoor flash photography may be selected only in response toan aperture stop setting. In this arrangement the construction may besimplified as the lever coupled to the shutter speed dial or ring may beeliminated.

What is claimed is:

1. An automatic flash selection device for use with a fullyautomaticexposure setting camera of the type having:

a. a housing with built-in flash equipment;

b. an exposure meter with a rotatable pointer;

c. a shutter speed mechanism;

d. a shutter stop mechanism;

e. a focusing mechanism; and

f. a shutter release;

wherein the improvement comprises:

g. a pointer stopper plate;

h. a detector plate connected to and adapted to be displaced with saidpointer stopper plate, in response to the actuation of the shutterrelease, a distance proportional to the angle of rotation of the pointerof the exposure meter, said plates being blocked during theirdisplacement by said pointer when the angle of rotation of said pointeris less than a predetermined angle and being displaced to the fulllength of their strokes when the angle of rotation is beyond apredetermined angle; i. a first lever rotatably pivoted to the housingand coupled to said detector plate for rotation during the displacementthereof;

j. a shutter blade driving pin for operating said shutter stop mechanismand adapted to be engaged by and driven under the control of said firstlever;

k. a shutter speed selection lever for controlling the operation of saidshutter speed mechanism;

1. an intermediate lever rotatably pivoted to the housing and adapted tobe rotated by said first lever and operatively coupled to said shutterspeed selection lever;

m. a focusing cam operated by said focusing mechanism;

11. a third level rotatably pivoted to the housing and adapted to engagesaid intermediate lever and said shutter blade driving pin;

whereby upon full displacement of said detector plate and stopper plate,said first and intermediate levers are rotated such that said thirdlever is disconnected from engagement with said intermediate lever so asto switch the engagement of said shutter blade driving pin by said firstlever to engagement by said focusing cam thereby putting said shutterstop mechanism under the control of said focusing mechanism while saidstopper plate actuates said flash equipment; and said shutter speedselection lever is moved by the rotation of said intermediate lever to aposition such that the shutter speed mechanism is operated at a lowshutter speed exposure.

1. An automatic flash selection device for use with a fullyautomaticexposure setting camera of the type having: a. a housing with built-inflash equipment; b. an exposure meter with a rotatable pointer; c. ashutter speed mechanism; d. a shutter stop mechanism; e. a focusingmechanism; and f. a shutter release; wherein the improvement comprises:g. a pointer stopper plate; h. a detector plate connected to and adaptedto be displaced with said pointer stopper plate, in response to theactuation of the shutter release, a distance proportional to the angleof rotation of the pointer of the exposure meter, said plates beingblocked during their displacement by said pointer when the angle ofrotation of said pointer is less than a predetermined angle and beingdisplaced to the full length of their strokes when the angle of rotationis beyond a predetermined angle; i. a first lever rotatably pivoted tothe housing and coupled to said detector plate for rotation during thedisplacement thereof; j. a shutter blade driving pin for operating saidshutter stop mechanism and adapted to be engaged by and driven under thecontrol of said first lever; k. a shutter speed selection lever forcontrolling the operation of said shutter speed mechanism; l. anintermediate lever rotatably pivoted to the housing and adapted to berotated by said first lever and operatively coupled to said shutterspeed selectIon lever; m. a focusing cam operated by said focusingmechanism; n. a third level rotatably pivoted to the housing and adaptedto engage said intermediate lever and said shutter blade driving pin;whereby upon full displacement of said detector plate and stopper plate,said first and intermediate levers are rotated such that said thirdlever is disconnected from engagement with said intermediate lever so asto switch the engagement of said shutter blade driving pin by said firstlever to engagement by said focusing cam thereby putting said shutterstop mechanism under the control of said focusing mechanism while saidstopper plate actuates said flash equipment; and said shutter speedselection lever is moved by the rotation of said intermediate lever to aposition such that the shutter speed mechanism is operated at a lowshutter speed exposure.